Surge in support for Brexit gives Remain just 1 point lead: poll

The Remain camp holds the slenderest of leads over Leave with a week to go until the Brexit referendum, according to a poll out Tuesday night.

A ComRes survey for the Sun newspaper puts Remain on 46 percent and Leave on 45 percent, a huge change from a Sun poll a month ago when the anti-Brexit camp had an 11 point lead.

The gap increases, but only slightly, when those who don't know which way they will vote are removed from the data, with Remain then ahead by 51-49 percent.

The big issue for voters appears to be immigration, with 47 percent saying they are concerned about the number of EU migrants coming to the U.K. That's a very similar figure to the those who are worried about the economy after a Brexit — 49 percent.